export {}

const numberArr: number[] = [1, 2, 3]
const stringArr: string[] = ['a', 'b', 'c']
const undefinedArr: undefined[] = [undefined, undefined]
const arr: (number | string)[] = [1, 'string', 2]

// type alias 类型别名
type lady = {name: string, age:number}

const girl1: {name:string, age:number}[] = [
    {name: 'mike', age: 18},
    {name: 'john', age: 18}
]

const girl2: lady[] = [
    {name: 'mike', age: 18},
    {name: 'john', age: 18}
]

class Madam {
    name: string;
    age: number;
}

const girl3: Madam[] = [
    {name: 'mike', age: 18},
    {name: 'john', age: 18}
]